Fracture types and how they heal

Question 1

Most common fracture <75years old

Answer 1

wrist fractures - esp COLLES

Question 2

What is a Colles fracture

Answer 2

fracture of DISTAL RADIUS -broken fragment of the radius tilts upward

Question 3

Cause of a Colles fracture

Answer 3

fall on an outstrecthed hand

Question 4

Most common clinical feature seen in Colles fracture

Answer 4

dinner-fork deformity

Question 5

Most common fracture >75yrs old

Answer 5

hip fracture (-osteoporosis + postmenopausal women)

Question 6

Why are hip fractures common >75yrs old?

Answer 6

trabeculae bone - faster rate of remodelling + larger S.A -more prone to fracture

Question 7

Define the following types of fractures:

1. closed
2. open
3. displaced

Answer 7

1. bone does not pierce skin
2. bone pierces skin
3. bone moves - fracture gap

Question 8

Which type of fractures are prone to infection + why?

Answer 8

open fractures - pierce skin - bacteria/fungi/ viruses - can enter body

Question 9

TRANSVERSE FRACTURE

1. define
2. cause

Answer 9

1. fracture at right angles to bone axis

2. stress fracture or sharp direct blow

Question 10

SPIRAL FRACTURE

1. define
2. cause
3. common sites

Answer 10

1. torsion fracture
2. rotating/twisting force is applied along the bone axis
3. humerus, fibula

Question 11

CRUSH FRACTURE

1. define
2. common sites
3. ass with which diseases

Answer 11

1. compression fracture - in CANCELLOUS BONE
2. vertebrae body -collapse anteriorly
3. osteoporosis

Question 12

BURST FRACTURE

1. define
2. cause

Answer 12

1. high energy load breaks vertebrae
2. trauma - landing on feet after a fall (force transmitted upwards to vertebrae)

*vertebrae compressed inbetween 2 IVD - IVD stronger than vertebrae bodies

Question 13

Name 2 fractures that can occur at the vertebrae

which is more severe

Answer 13

1. crush/compression fractures
2. burst fractures

burst - typically damages nerve- neurological deficit

Question 14

AVULSION FRACTURE

1. define
2. seen in which individuals
3. common sites

Answer 14

1. tendon/ligament + bone its attached to pull away from main part of the bone
2. young athletes
3. hip flexors - pelvis
   hamstrings -pelvis
   inner forearm muscles - inner elbow

Question 15

What is a fracture disloaction

Answer 15

• fracture involving a JOINT

- MAL-ALIGNMENT of joint surface

Question 16

Difference between dislocation and subluxation

Answer 16

disloaction - complete mal-allignment of joint

subluxation - partial/incomplete dislocation

Question 17

What is an impacted fracture?

Answer 17

2 BONE FRAGMENTS ARE DRIVEN INTO EACH OTHER

Question 18

What is a comminuted fracture?

Answer 18

bone fragments into >2pieces

Question 19

What is a stress fracture?

Answer 19

• abnormal stress on a normal bone

- normal stress on an abnormal bone (osteoporosis, paget’s)

Question 20

What is a periosteal reaction?

Answer 20

formation of new bone in response to injury

on x-ray- whiter area- osteoblast activity

Question 21

GREENSTICK FRACTURE

1. define
2. seen in which individuals

Answer 21

1. soft, immature bone BENDS WITHOUT COMPLETELY FRACTURING

2. children - higher proportion of woven:lamellar bone

Question 22

Why are stress fracture difficult to detect via X-ray?

Answer 22

• involve trabeculae bone NOT cortical bone
• therefore occur INSIDE the bone
• difficult to identify on X-ray

Question 23

What is bone scintigraphy?

Answer 23

inject radioactive isotope- picked up by dividing osteoblasts- shows unusual bone rebuilding activity

Question 24

What test/investigation can be used to detect stress fractures?

Answer 24

bone scintigraphy

Question 25

Name 2 fractures common in children

Answer 25

1. greenstick

2. fractures to the epiphyseal growth plate (EGP)

Question 26

Why can fractures to the EGP occur?

Answer 26

EGP - chrondyctes - softer than bone - easier to fracture

Question 27

What can happen as a result of a fracture to EGP?

Answer 27

EGP fracture - premature closure of EGP -stunted/abnormal growth

Question 28

What are the 4 stages of fracture healing?

Answer 28

1. fracture haematoma
2. fibrocartilaginous callus
3. bony callus
4. bone remodelling

Question 29

Describe the fracture haematoma stage in fracture healing

Answer 29

• blood vessels damaged by fracture
• blood leaks out into bone
• platelets activated- CLOT
• inflammatory cells enter (macr,wbcs) -clear debris (dead osteoblasts/clasts) around fracture site
• swelling + inflammation = LIFTS PERIOSTEUM

Question 30

How long does the fracture haemtoma process take place

Answer 30

+6-8hrs

Question 31

Describe the fibrocollagenous callus stage in fracture healing

Answer 31

`1.ANGIOGENESIS

• organises fracture haemtoma -granulation tissue (PROCALLUS
  2. FIBROBLASTS + OSTEOGENIC CELLS invade procallus
  
  • differentiate to chrondrocytes
    
    3. chondrocytes - secrete collagen type 1 (bind 2 bone ends together)

FIBROBLASTS- secretes chondrocytes quicker than osteoblasts - PRODUCE FIBROCARTILAGE - FIBROCARTILAGINOUS CALLUS

Question 32

How long does the fibrocartilaginous callus process take

Answer 32

3 weeks

Question 33

Describe the bony callus stage in fracture healing

Answer 33

1. osteoblasts fully differentiated (+3wks fracture)

2. lay down WOVEN BONE

Question 34

How long does bony callus process take

Answer 34

3-4months

starts 3wks post fracture

Question 35

Describe the bone remodelling stage in fracture healing

Answer 35

WOVEN - LAMELLAR

Question 36

Which cells are responsible for bone remodelling

Answer 36

osteoclasts